A subject of the present invention is two new crystalline forms of 1S-[1alpha(2S*,3R*),9alpha]6,10-dioxo-N-(2-ethoxy-5-oxo-tetrahydro-3-furanyl)-9[[(1-isoquinolyl)carbonyl]amino]octahydro-6H-pyridazino[1,2-a][1,2]diazepin-1-carboxamide (anhydrous or hydrated), their preparation process and the pharmaceutical compositions containing them.
Patent Application WO 9722619 describes 1S-[1-alpha(2S*,3R*) 9alpha]6,10-dioxo-N-(2-ethoxy-5-oxo-tetrahydro-3-furanyl)-9[[(1-isoquinolyl)carbonyl]amino]octahydro-6H-pyridazino[1,2-a][1,2-]diazepin-1-carboxamide as well as its pharmaceutically acceptable salts (product 412f: Compound I) as inhibitors of the interleukin-1beta conversion enzyme: 
Compound (I) as described and prepared in this Application WO9722619 is found in amorphous form. It mainly has the drawback of being hygroscopic.
The preparation of compound (I) is carried out in the following way: Amidification reaction between (1S,9S)9-(isoquinolin-1-oylamino)-6,10-dioxo-1,2,3,4,7,8,9,10-octahydro-6H-pyridazino-[1,2-a][1,2]-diazepin-1-carboxylic acid and (3S,2S)3-allyloxycarbonylamino-2-benzyloxy-5-oxotetrahydrofuran in the presence of dimethylbarbituric acid, tetrakistriphenylphosphine palladium, 1-hydroxybenzotriazole and 1(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride in methylene chloride, dimethylformamide or a mixture of these two solvents. The product is purified by chromatography (Ethyl acetate/dichloromethane) in order to produce amorphous compound (I).
A subject of the invention is to find one or more new crystalline forms which do not have the drawbacks of the amorphous form.
The solid forms, and in particular the pharmaceutical products, can have more than one crystalline form. This is what is called polymorphism.
The polymorphous forms of the same molecule in general show different physical properties such as solubility, hygroscopicity and stability. It should be noted that for the moment methods do not exist which allow the existence of such-and-such a polymorph, nor their physical properties to be predicted.
Obtaining new polymorphous forms of molecules having a therapeutic activity is of great interest to the pharmaceutical industry in particular from the point of view of their preparation on an industrial scale, their use in pharmaceutical compositions, the search for better stability and better bioavailabilty. (Byrn, S. R., Solid-State Chemistry of Drugs, New York, Academ. Press (1982); Kuhnert-Brandstatter, M, Thermomicroscopy In the Analysis of Pharmaceuticals, New York, Pergamon Press (1971); J. Halebian et al. J. Pharm. Science (1969) vol 58(8) 911; J. Halebian et al. J. Pharm. Science (1975) vol 64(8) 1269-1288).
By polymorphous form is meant all asolvated forms of a crystallized molecule, and by pseudo-polymorphous form all solvated forms.